In a conventional direct-view liquid crystal display, there is produced a difference in a picture birefringence phase difference (retardation), depending on the angle of visibility (angle with which the display is viewed), with the result that the picture displayed on the display appears as if the picture has been changed in color. This problem is routinely coped with by an optical compensation plate introduced between the optical compensation plate and the liquid crystal layer to improve the retardation.
Although sufficient improvement may be achieved in case of displaying black (lowest luminance) or white (highest luminance), such is not the case with displaying intermediate luminance. For example, even though the input grayscale-luminance characteristics are γ characteristics shown at P in FIG. 30, with the angle of visibility of 0° (in case of viewing the display from the front side), the input grayscale-luminance characteristics in case of viewing the display at an angle of visibility of 60° (in case of viewing the display from an angle of 60°) depart from the γ characteristics, as indicated at Q in FIG. 30.
Meanwhile, the processing for improving display characteristics for moving pictures, termed over-drive processing and black-insertion processing, is used in a direct-viewing liquid crystal display. The over-drive processing is a technique of slightly increasing the driving voltage for the liquid crystal, in case a picture is transitioning, in such a manner as to raise follow-up characteristics of the liquid crystal. The black-insertion processing is the processing of displaying a black picture before a picture image transitions to the next picture image to prohibit the picture image from becoming blurred due to a residual image on the retina of the human eye.